So heres the short version of the story:
Bought 4 new tires dec' 06. Front tires were worn on the inside so I bought 2 new tires about 3 weeks ago. I have a lifetime alignment policy with Discount Tire Center so I took it to them to get the front aligned. I personally think they've been doing crappy jobs so I took the car to Just Tires to get a free alignment check. They told me the front alignment was still off, so I took it back to Discount Tire again to get another alignment. They told me that everything is still okay, and that the car only moved like 0.1 from spec.

I have both print outs from Discount Tires and Just Tires, but I really have no idea how to read it correctly. Since one says the alignment is fine, and the other says the alignment is off; are they both using the correct spec's to align it? Thats about all I could think of, is that they might be using 2 different mercedes specs?

 

Yeah, the specs seem to vary a bit but the numbers aren't so far off to be concerned. The data provided is from their program look-ups provided for the alignment equipment in ranges not necessarily called out by MB.

A good front-end guy will align for symmetry using specs as a guide not an absolute. The end numbers should be close to spec but they are using experience not just numbers. The "free" check shop of course will find its off even if not noticeable or effecting tire life. They hope to hook you.

Uneven tire wear can be a result of front end wear that alignments will never correct. Does the car pull left or right when pointed straight? Okay - so it tracks straight, you monitor pressure and rotate your tires. Watch for signs of inner wear which is camber way out of adjustment. This would be obvious to even a lame tech. Ask the shop what the common cause of inside tire wear is and have them check it again. Also have them inspect the tie-rod ends, ball joints etc. They may be missing something not related to alignment.

 

Give Les Schwab a try.

 

Am I reading the charts correctly?... the camber specification is different on each list. Just Tires lists the spec as 0° to +0.5°. Camber should be slightly negative.

 

unfortunately, Les Schwab is 300 miles away....

White_Knuckles - what do you mean by front end wear? My car seemed like its always had suspension problems. It will always pull right or left, and wont stay straight if I let go of the wheel. I'll have to monitor the pressure and wear so these tires dont go in 6 months like the first ones.

 

XO3, By "front-end wear", I'm talking about all the mechanical components that perform steering and suspension action. Excessively worn ball joints may cause uneven tire wear and thuds going over bumps. Worn tie-rod ends can create pull or wander. There are many front-end parts that simply wear with normal use even if your car was properly lubed.

It's a 1990. I see your mileage at over 200K. The front end may need far more attention than an alignment. Find a qualified shop that will test A-arms, ball joints, wheel bearing play, bushings, tie-rod ends etc. It only takes about 20 minutes. Then ask them what may be effecting your tires and handling. I'm suggesting your focus is on alignment where the issues may be elsewhere.

These cars do wander slightly as you described. If a car has a true alignment issue it will favor one direction such as - pulls to the right and is quite noticeable. Don't forget tire rotation to get the most tire life.

 

Squirrely handling can also happen if the springs are worn and sag. See if you can check the ride height. One inch sag can make a difference.

 

both technicians last names were wong... maybe it's a conspiracy? haha

 

Yeah considering how old the car is, I'll have to get the other suspension parts checked out like you said. Im sure I could take it to TWS, but anybody know of any other shops that specialize in suspension stuff in socal?

 

x03 your name chanages on those tickets, do you have split personalities?

 

We do have a humble shop here in the Philippines, we may not have the top-of-the-line equipment but decent enough to guide our technicians how to work on the cars. One thing that we religiously do is to calibrate our equipment (4-wheel aligner included) on a regular basis. This ensures that we get accurate readings.

Maybe you can aslo ask the shop you plan to bring your car how recent did they have it calibrated.

As far as specs are concerned, from Haynes:
Camber:
Estate -0deg 5mins
All other model -0deg 25mins

Caster:
Left hand 10deg
Right hand 11deg

Total Toe setting: 0deg 20mins

REAR WHEEL:
Camber -1deg 30min
Total Toe 0deg 25min

 

Man, he tried to trick 'em that he was a different guy with different cars. That way they couldn't cheat the numbers.

 

haha not exactly, the car is registered under my dads name for discount tires, but I put down my own name at just tires. Neither of them knew that I took it to another alignment shop.

So talking with my bro, here is some info that he told me.
So i took a look at them, and yea its hard to say which one is correct.
Unless you pull from a tech manual specific to this car what are the correct
specs, its impossible to really say which one should be right. But if you
are getting inner tire wear then i would say that Just tires might be more
correct because negative camber will result in inner tire wear, it doesnt
really make sense to have negative camber on a car like yours. Having the
proper Toe is going to be most important to get accurate tire position to
reduce the inner tire wear. That may make more difference then the camber,
and according to Just tires, your Toe IS off.